1. Field of the Invention
The present invention relates to a gate valve and more particularly to a gate valve for use in a processing device for processing a semiconductor wafer or the like.
2. Description of the Prior Art
In a processing device for processing a semiconductor wafer, a liquid crystal substrate or the like to be processed, the wafer or the like is inserted into or taken out from a processing chamber through an opening formed in a wall of the processing chamber having a gate valve.
Such gate valve is described in U. S. Pat. No. 5,120,019.
FIG. 9 shows an essential portion of a conventional semiconductor wafer manufacturing apparatus. A reference numeral 1 denotes a processing chamber, 2 denotes a semiconductor wafer or the like to be processed in the processing chamber 1, 3 denotes a transfer chamber for transferring the semiconductor wafer 2 into the processing chamber 1,4 denotes a partition wall having a thickness of 20 mm, for example, for separating both chambers 1 and 3, 5 denotes a rectangular opening having a length of about 50 mm and a width of about 230 mm formed in the wall 4, through which the wafer 2 is transferred, 6 denotes a rectangular plate xe2x80x94like valve disc for opening and closing the opening 5 arranged in the transfer chamber 3 so as to face to a valve seat formed on the wall 4 around the rectangular opening 5 through an O-ring 7 provided on the valve disc 6, 8 denotes a valve rod connected to the valve disc 6 for moving the valve disc 6 in a horizontal direction, for example, so that the valve disc 6 is brought into engagement with the valve seat through the O-ring 7 or disengagement with the valve seat, and for moving up and down or in a direction normal to the horizontal direction when the valve disc 6 is separated from the valve seat, and 9 denotes a current of corrosion gas and/or plasma for processing the semiconductor wafer 2 in the processing chamber 1.
When the wafer 2 is processed in such processing chamber 1, the opening 5 is closed by the valve disc 6 positioned in the transfer chamber 3, so that a space or concave portion corresponding to the thickness of the wall 4 is formed in the opening 5. Accordingly, the current 9 of the gas and/or plasma in the processing chamber 1 is disturbed by the concave portion as a current 9xe2x80x2 shown in FIG. 9. This results in the quality of the wafer 2 to be lowered. Further, the seal portion of the valve disc 6 is exposed to the processing chamber 1, so that the seal portion or the O-ring 7 is attacked and polluted by the corrosion gas and/or plasma.
Accordingly, it is an object of this invention to provide a gate valve free from the above defects.
This invention can be summarized as follows.
A gate valve comprising a valve disc for opening and closing an opening formed in a partition wall for separating a processing chamber from an other chamber, a block provided on a side surface of the valve disc facing the processing chamber for filling the opening, and means for moving the valve disc so that said valve disc is selectively brought into contact with a side surface of the partition wall facing the processing chamber to close the opening, wherein when the opening is closed by the valve disc the block is positioned in the opening, and when the opening is not closed by the valve disc the block is not positioned in the opening.
The invention can also be summarized as follows.
A gate valve comprising a valve disc for opening and closing an opening formed in a partition wall for separating a processing chamber from an other chamber, a closing member for opening and closing one side of the opening facing the processing chamber, a groove formed in the wall for receiving therein the closing member, and means for driving the valve disc and the closing member selectively to a position where said valve disc is brought into contact with a side surface of the partition wall facing said other chamber and said closing member is positioned at the one side of the opening to close the opening, and a position where said valve disc is separated from the partition wall and the closing member is inserted into the groove.
The invention can also be summarized as follows.
A gate valve comprising a valve disc for opening and closing an opening formed in a partition wall for separating a processing chamber from an other chamber, a closing member for opening and closing one side of the opening facing the processing chamber, means for moving the valve disc and the closing member relative to each other, and means for driving the valve disc and the closing member selectively to a position where said valve disc is brought into contact with a side surface of the partition wall facing said other chamber and said closing member is positioned at the one side of the opening to close the opening, and a position where said valve disc is separated from the partition wall and the closing member is moved in the processing chamber.
Said means for moving the valve disc and the closing member relative to each other comprises a bellows one end of which is fixed to the valve disc and the other end of which is connected to the closing member, and means for applying a fluid pressure into the bellows to expand the bellows.
Said side surface of the wall facing the processing chamber is curved, and the closing member and the groove are curved in conformity with the curve of said surface of the wall.
Said side surface of the wall facing the processing chamber is curved, and the closing member is curved in conformity with the curve of said side surface of the wall.
These and other aspects and objects of the present invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following description, while indicating preferred embodiments of the present invention, is given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.